ソフトウェアエンジニアの技術ブログ：Software engineer tech blog

use serde::{Deserialize, Serialize};

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {

    #[derive(Deserialize, Serialize)]
    struct Ip {
        ip: String,
    }

    let uri = "https://httpbin.org/post";
    let data = &Ip {
        ip: "129.0.0.1".into(),
    };
    let mut res = surf::post(uri).body_json(data)?.await?;
    let body = res.body_string().await?;
    println!("{}", body);

    let uri = "https://api.ipify.org?format=json";
    let Ip { ip } = surf::get(uri).recv_json().await?;
    println!("{}", ip);
    assert!(ip.len() > 10);
    Ok(())
}

Postができる。actix-webでpostされたデータを受け取ることができるかは要確認。

まずはGetリクエストから

use async_std::task;

fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
    task::block_on(async {
        let mut res = surf::get("https://httpbin.org/get").await?;
        dbg!(res.body_string().await?);
        Ok(())
    })
}

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync + 'static>> {
    let mut res = surf::get("https://httpbin.org/get").await?;
    dbg!(res.body_string().await?);
    Ok(())
}

[src/main.rs:4:5] res.body_string().await? = “{\n \”args\”: {}, \n \”headers\”: {\n \”Accept\”: \”*/*\”, \n \”Accept-Encoding\”: \”deflate, gzip\”, \n \”Host\”: \”httpbin.org\”, \n \”User-Agent\”: \”curl/8.11.0-DEV isahc/0.7.6\”, \n \”X-Amzn-Trace-Id\”: \”Root=1-676a57b7-3de7e4ff65be3baf597f36f8\”\n }, \n \”origin\”: \”106.155.3.182\”, \n \”url\”: \”https://httpbin.org/get\”\n}\n”

### actix-web
$ cargo new my_web_app
$ cd my_web_app

[dependencies]
actix-web = "4"

main.rs

use actix_web::{web, App, HttpResponse, HttpServer, Responder};

async fn greet() -> impl Responder {
    HttpResponse::Ok().body("Hello, world!")
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(||{
        App::new()
            .route("/", web::get().to(greet))
    })
    .bind("127.0.0.1:8080")?
    .run()
    .await
}

$ curl 127.0.0.1:8080
Hello, world!

ほう

### Rocket
$ cargo new rocket_web_app
$ cd rocket_web_app
$ rustup override set nightly

#[macro_use] extern crate rocket;

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[launch]
fn rocket() -> _ {
    rocket::build().mount("/", routes![index])
}

$ cargo run
Compiling rocket_web_app v0.1.0 (/home/vagrant/dev/rust/rocket_web_app)
error[E0463]: can’t find crate for `rocket`
–> src/main.rs:1:14
|
1 | #[macro_use] extern crate rocket;
| ^^^^^^^^^^^^^^^^^^^^ can’t find crate
….

rocketの方は色々エラーが出るので、少し触った感じではactix-webの方が使いやすそう..

遅いリクエストを実装

use std::thread;
use std::time::Duration;

// 

    let get = b"GET / HTTP/1.1\r\n"; 
    let sleep = b"GET /sleep HTTP/1.1\r\n"; 

    let(status_line, filename) = if buffer.starts_with(get) {
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else if buffer.starts_with(sleep){
        thread::sleep(Duration::from_secs(5));
        ("HTTP/1.1 200 OK\r\n\r\n", "hello.html")
    } else {
        ("HTTP/1.1 404 NOT FOUND\r\n\r\n", "404.html")
    };

### スレッドプール
タスクを処理する準備のできた一塊の大量に生成されたスレッド
ただし、固定された数のスレッドにすることで、無制限に大量生産してDos攻撃の被害に遭うことを抑える。

fn main() {
    let listner = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listner.incoming() {
        let stream = stream.unwrap();

        thread::spawn(||{
            handle_connection(stream);
        });
    }
}

スレッド数を限定する

use std::thread;

pub struct ThreadPool {
    workers: Vec<Worker>,
}

impl ThreadPool {
    pub fn new(size: usize) -> ThreadPool {
        assert!(size > 0);

        let mut threads = Vec::with_capacity(size);

        for _ in 0..size {
            workers.push(Worker::new(id));
        }
        ThreadPool {
            workers
        }
    }

    pub fn execute<F>(&self, f: F)
        where
            F: FnOnce() + Send + 'static
    {

    }
}

struct Worker {
    id: usize,
    thread: thread::JoinHandle<()>,
}

impl Worker {
    fn new(id: usize) -> Worker {
        let thread = thread::spawn(||{});

        Worker {
            id,
            thread,
        }
    }
}

use std::thread;
use std::sync::mpsc;
use std::sync::Arc;
use std::sync::Mutex;

pub struct ThreadPool {
    workers: Vec<Worker>,
    sender: mpsc::Sender<Job>,
}

trait FnBox {
    fn call_box(self: Box<Self>);
}

impl<F: FnOnce()> FnBox for F {
    fn call_box(self: Box<F>){
        (*self)()
    }
}

type Job = Box<dyn FnBox + Send + 'static>;


impl ThreadPool {
    pub fn new(size: usize) -> ThreadPool {
        assert!(size > 0);

        let(sender, receiver) = mpsc::channel();

        let receiver = Arc::new(Mutex::new(receiver));

        let mut workers = Vec::with_capacity(size);

        for id in 0..size {
            workers.push(Worker::new(id, Arc::clone(&receiver)));
        }
        ThreadPool {
            workers,
            sender,
        }
    }

    pub fn execute<F>(&self, f: F)
        where
            F: FnOnce() + Send + 'static
    {
        let job = Box::new(f);
        self.sender.send(job).unwrap();
    }
}

struct Worker {
    id: usize,
    thread: thread::JoinHandle<()>,
}

impl Worker {
    fn new(id: usize, receiver: Arc<Mutex<mpsc::Receiver<Job>>>) -> Worker {
        let thread = thread::spawn(move||{
            loop {
                let job = receiver.lock().unwrap().recv().unwrap();

                println!("Worker {} got a job; executing.", id);
                job.call_box();
            }
        });

        Worker {
            id,
            thread,
        }
    }
}

Worker 0 got a job; executing.
Worker 1 got a job; executing.
Worker 2 got a job; executing.
Worker 3 got a job; executing.
Worker 0 got a job; executing.

unwrap()は、OptionがSomeの場合はその中の値を返し、Noneの場合はパニックを引き起こす。

fn main(){
    let value = Some(10);
    let v = value.unwrap();
    println!("v: {}", v);
}

Rustの「unwrap」と「?」はエラーハンドリングに使われる方法
unwrapはOption型やResult型の値がSomeやOkであることを前提として値を取り出す。NoneやErrだった場合は、panic!マクロが呼ばれてプログラムがクラッシュする。
?演算子は、Okの場合は値を返し、Errの場合はそのErrを呼び出し元に返す。

なるほど、OptionとResultがわかってないと、unwrapと?もさっぱり理解できませんね。。

Resultは、失敗するかもしれない処理の結果を表現する列挙型。

enum Result<T, E>{
    Ok(T),
    Err(E),
}

fn get_value_bad(v: bool, result: &mut usize) -> usize {
    if v {
        *result = 100;
        true
    } else {
        false
    }
}

fn get_value_good(v: bool) -> Result<usize, &'static str> {
    if v {
        OK(100)
    } else {
        Err("error message")
    }
}

fn main(){
    let mut result = 0;
    if get_value_bad(true, &mut result){
        println!("success: {}", result);
    } else {
        println!("failure");
    }

    match get_value_good(true){
        Ok(result) => println!("success: {}", result),
        Err(msg) => println!("failure")
    }
}

fn plus_one(x: Option<i32>) -> Option<i32> {
    match x {
        None => None,
        Some(i) => Some(i + 1),
    }
}

fn main(){
    let five = Some(5);
    let six = plus_one(five);
    let none = plus_one(None);
}

use std::fs::File;

fn main(){
    let f = File::open("hello.txt");

    let _f = match f {
        Ok(file) => file,
        Err(error) => {
            panic!("There was a problem opening the file: {:?}", error);
        }
    };
}

OptionはSome, None, ResultはOk, Errで共にエラーハンドリングなどで使うのね。

無効な値を取ることができる便利な列挙型としてOption型がある。

enum Option<T>{
    Some(T),
    None,
}

まず列挙型について
C++の列挙型

#include <stdio.h>

enum week {
    Mon,
    Tue,
    Wed,
    Thu,
    Fri,
    Sat,
    Sun,
};

int main(void) {
    enum week wk0, wk1, wk2;

    wk0 = Mon;
    wk1 = Tue;
    wk2 = Thu;

    printf("Monの値は:%d\n", wk0);
    printf("Tueの値は:%d\n", wk1);
    printf("Thuの値は:%d\n", wk2);
}

#[derive(Debug)]
enum Week {
    Mon,
    Tue,
    Wed,
    Thu,
    Fri,
    Sat,
    Sun
}

fn main(){
    let wk0 = Week::Mon;
    let wk1 = Week::Tue;
    let wk2 = Week::Thu;

    println!("Monの値は{:?}", wk0);
    println!("Tueの値は{:?}", wk1);
    println!("Wedの値は{:?}", wk2);
}

$ ./main
Monの値はMon
Tueの値はTue
Wedの値はThu
rustだと、c++のように0,1,2…ではなく、値がそのまま出てくる。

### Option
取得できないかもしれない値を表現する列挙型
値が無いことを示すNoneと、あることを示すSome(T)のどちらかを取る

pub enum Option<T> {
    None,
    Some(T),
}

fn get_value_bad(v: bool, result: &mut usize) -> bool {
    if v {
        *result = 100;
        true
    } else {
        false
    }
}

fn get_value_good(v: bool) -> Option<usize> {
    if v {
        Some(100)
    } else {
        None
    }
}

fn main(){
    let mut result = 0;
    if get_value_bad(true, &mut result){
        println!("success: {}", result);
    } else {
        println!("failure");
    }

    match get_value_good(true){
        Some(result) => println!("success: {}", result),
        None => println!("failure")
    }
}

$ cargo new hello –bin

use std::net::TcpListener;

fn main() {
    let listner = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listner.incoming() {
        let stream = stream.unwrap();
        println!("Connection established!");
    }
}

ターミナルから、リクエストを送信する
$ ping http://127.0.0.1:7878/
ping: http://127.0.0.1:7878/: Name or service not known

すると、サーバ側では、
Running `target/debug/hello`
Connection established!
Connection established!
Connection established!
Connection established!
…

use std::io::prelude::*;
use std::net::TcpStream;
use std::net::TcpListener;

fn main() {
    let listner = TcpListener::bind("127.0.0.1:7878").unwrap();

    for stream in listner.incoming() {
        let stream = stream.unwrap();
        handle_connection(stream);
    }
}

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0; 1024];

    stream.read(&mut buffer).unwrap();

    println!("Request: {}", String::from_utf8_lossy(&buffer[..]));
}

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0; 1024];
    stream.read(&mut buffer).unwrap();

    let mut file = File::open("hello.html").unwrap();

    let mut contents = String::new();
    file.read_to_string(&mut contents).unwrap();

    let response = format!("HTTP/1.1 200 OK\r\n\r\n", contents);
    stream.write(response.as_bytes()).unwrap();
    stream.flush().unwrap();
}

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0; 1024];
    stream.read(&mut buffer).unwrap();

    let mut file = File::open("hello.html").unwrap();

    let mut contents = String::new();
    file.read_to_string(&mut contents).unwrap();

    let response = format!("HTTP/1.1 200 OK\r\n\r\n{}", contents);
    stream.write(response.as_bytes()).unwrap();
    stream.flush().unwrap();
}

これで、curl http://127.0.0.1:7878を打つと、htmlが返ってくる

fn handle_connection(mut stream: TcpStream) {
    let mut buffer = [0; 1024];
    stream.read(&mut buffer).unwrap();

    let get = b"GET / HTTP/1.1\r\n"; 

    if buffer.starts_with(get) {
        let mut file = File::open("hello.html").unwrap();
        let mut contents = String::new();
        file.read_to_string(&mut contents).unwrap();

        let response = format!("HTTP/1.1 200 OK\r\n\r\n{}", contents);
        stream.write(response.as_bytes()).unwrap();
        stream.flush().unwrap();
    } else {
        let status_line = "HTTP/1.1 404 NOT FOUND\r\n\r\n";
        let mut file = File::open("404.html").unwrap();
        let mut contents = String::new();

        file.read_to_string(&mut contents).unwrap();

        let response = format!("{} {}", status_line, contents);

        stream.write(response.as_bytes()).unwrap();
        stream.flush().unwrap();
    }    
}

### jsonの読み込み

use serde::{Serialize, Deserialize};
use std::fs;
use std::io::prelude::*;

#[derive(Serialize, Deserialize, Debug)]
#[allow(non_snake_case)]
struct Rotator {
    Pitch:f32,
    Roll:f32,
    Yaw:f32,
}

#[derive(Serialize, Deserialize, Debug)]
#[allow(non_snake_case)]
struct CharaParam {
    Name: String,
    Id: i32,
    ItemIdList: Vec<u32>,
    RotData:Rotator,
}

fn main(){
    let input_fn = fs::read_to_string("src/test_input.json")
        .expect("JSON Read Failed.");
    let deserialized: Vec<CharaParam> = serde_json::from_str(&input_fn).unwrap();

    for data in &deserialized {
        println!("{:?}", data);
    }
}

### jsonの書き出し

use serde::{Serialize, Deserialize};
use std::fs::File;
use std::io::prelude::*;

#[derive(Serialize, Deserialize, Debug)]
#[allow(non_snake_case)]
struct Rotator {
    Pitch:f32,
    Roll:f32,
    Yaw:f32,
}

#[derive(Serialize, Deserialize, Debug)]
#[allow(non_snake_case)]
struct CharaParam {
    Name: String,
    Id: i32,
    ItemIdList: Vec<u32>,
    RotData:Rotator,
}

fn main(){
    let chara00 = CharaParam{Name:String::from("Apple"), Id:0x01, ItemIdList:vec![1000, 1001], RotData:Rotator{Pitch:0.0, Roll:0.0, Yaw:32.0} };
    let chara01 = CharaParam{Name:String::from("Banana"), Id:0x02, ItemIdList:vec![1002, 1003], RotData:Rotator{Pitch:0.0, Roll:-70.0, Yaw:66.0} };

    let mut param_list:Vec<CharaParam> = Vec::new();
    param_list.push(chara00);
    param_list.push(chara01);

    let output_fn = String::from("src/test_output.json");
    let result = output_json(&output_fn, param_list);
    match result {
        Ok(..) => {println!("Json Output Finished. [{}]", output_fn)}
        Err(err) => {println!("Error! : {}", err)}
    }
}

fn output_json(output_fn: &str, charaparam_list: Vec<CharaParam>) -> std::io::Result<()> {
    let serialized: String = serde_json::to_string(&charaparam_list).unwrap();
    let mut file = File::create(output_fn)?;
    file.write_all(serialized.as_bytes())?;
    Ok(())
}

serde_json::to_string(&charaparam_list).unwrap();　でstring型にしていますね。

つまりこういうことかな？

use serde::{Serialize, Deserialize};
use std::io::prelude::*;
use hex_literal::hex;
use k256::{ecdsa::{SigningKey, Signature, signature::Signer, signature::Verifier, VerifyingKey}};
use chrono::{Utc, Local, DateTime, Date};

#[derive(Serialize, Deserialize, Debug)]
struct UnsignedTransaction {
    time: String,
    sender: String,
    receiver: String,
    amount: i32,
}

#[derive(Serialize, Deserialize, Debug)]
struct SignedTransaction {
    time: String,
    sender: String,
    receiver: String,
    amount: i32,
    signature: String,
}

fn hex(bytes: &[u8]) -> String {
    bytes.iter().fold("".to_owned(), |s, b| format!("{}{:x}", s, b))
}

fn main(){
    let private_key: SigningKey = SigningKey::from_bytes(&hex!(
        "DCDFF4B7CA287CC7BD30ECAEF0622265DB4E14054E12954225457C3A6B84F135"
    ).into()).unwrap();
    let public_key: &VerifyingKey = private_key.verifying_key();
    let public_key_str = hex(&public_key.to_encoded_point(false).to_bytes());
    let public_key_b_str = "4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991124";

    let utc_datetime: DateTime<Utc> = Utc::now();
    let ut1 = UnsignedTransaction {time: utc_datetime.to_string(), sender: public_key_str.to_string(), receiver: public_key_b_str.to_string(), amount: 10};
    println!("{:?}", ut1);
    let serialized: String = serde_json::to_string(&ut1).unwrap();
    let sig1: Signature = private_key.sign(serialized.as_bytes());
    let signed_ut1 = SignedTransaction {time: utc_datetime.to_string(), sender: public_key_str.to_string(), receiver: public_key_b_str.to_string(), amount: 10, signature: sig1.to_string()};
    println!("{:?}", signed_ut1);

}

UnsignedTransaction { time: “2024-12-22 00:30:45.843926032 UTC”, sender: “4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991123”, receiver: “4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991124”, amount: 10 }
SignedTransaction { time: “2024-12-22 00:30:45.843926032 UTC”, sender: “4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991123”, receiver: “4bac6cb0f4ad6397752c3d73b88c5c86e3d88ac695118494a1732e2abd16c76acad3d6586c37c8db7e69c2f812f99275198936957d72c38d71981991124”, amount: 10, signature: “301DC132F45B1F8D0734A51E73F6725260B5365FBC9C2C405B9A12C70B97E47842366C2EC589F05AF8715268BC5A954B487F234F5FD3157ADBE8940AF2037B60” }

シリアライズしてバイトにしてsignする。。
しかし、これだとうまくいかん…

    let pubkey = signed_ut1.sender;
    let sig = signed_ut1.signature;

    let verified = pubkey.verify(ut1, &sig).is_ok();

    if verified {
        println!("文章は改竄されていません。");
    } else {
        println!("文章が改竄されています。");
    }